Dot counting test time and errors in U.S. veterans

Prior studies have explored potential improvements to the Dot Counting Test's efficiency at detecting invalid neuropsychological performance. The present study examined the classification accuracy and clinical utility of typical scoring (E-score), total response time, error scores, and two abbreviated versions.

United States military veterans within the VA healthcare system, n=137, mean age=39.1 (SD=9.0), were administered a battery of neuropsychological tests including the DCT and seven other performance validity tests. These veterans were referred for current cognitive complaints in the context of a reported history of head injury and were OIF/OEF/OND era veterans evaluated between 2016 and 2023. .

Sensitivity and specificity at various cutoff scores were calculated for all variables. The highest classification accuracy at an optimal specificity level was found for the full DCT time score and the DCT-6 time score (for both, sensitivity = 64.3, specificity = 92.6).

While the classification accuracy for the E-score was strong, accuracy of the total time score and DCT6 time score were slightly better in this sample. The advantage of time-only scores was demonstrated in this study while the inclusion of error count in DCT score was shown to have a negligible benefit to classification accuracy. All DCT indices evaluated herein, E-scores and time-only scores for the full test and abbreviated forms, demonstrated effective classification accuracy and are supported for use in evaluations with younger veterans and similar clinical populations.